1. Field of the Invention
The present invention relates to an apparatus and method for driving a liquid crystal display (LCD) device to prevent error of a timing controller when performing frequency conversion, thereby preventing display of defective images.
2. Discussion of the Related Art
Generally, a liquid crystal display (LCD) device can display various images by controlling light transmittance using driving circuits. The LCD device includes a liquid crystal display part that displays the images and a driving circuit that controls the liquid crystal display part. In particular, the liquid crystal display part includes a plurality of sub pixels that form pixel matrices, a plurality of thin film transistors that respectively drive the sub pixels, a plurality of gate lines that respectively control the thin film transistors, and a plurality of data lines that respectively supply data to the thin film transistors. The driving circuit includes a gate driver that drives the gate lines of the liquid crystal display part, a data driver that drives the data lines of the liquid crystal display part, and a timing controller that controls the gate driver and the data driver. The timing controller aligns video data input from the exterior, and supplies the aligned video data to the data driver. Also, the timing controller controls the timing of the gate driver and the data driver by using a plurality of synchronizing signals input from the exterior.
In the related art LCD device, a screen where the image is to be displayed may display a defective image during the process of converting driving frequencies for low power consumption. For example, if a frame frequency of 60 Hz is converted to a frame frequency of 50 Hz, the plurality of synchronizing signals are also modulated and supplied to the timing controller at a frequency that is appropriate for the frame frequency of 50 Hz. The timing controller controls the gate driver and the data driver with the synchronizing signals according to this modulated frequency. Therefore, the liquid crystal display part can display an image with a frame frequency of 50 Hz. However, when converting the frame frequency, the synchronizing signals are unstable and therefore may cause error of the timing controller. Thus, it results in display of defective images, examples of which include the unstable image being displayed in the liquid crystal display part, or a message of “no signal” being displayed in the liquid crystal display part.